Material blending



April 4, 1944. P. H. BURDETT 2345554 MATERIA BLENDING Filed Aug. 28, 1942 2 sheetsaneet 1 AGE April 4, 1944. H, BURDETT 2,345,554

MATERIA. BLBNDING Filed Aug. '28, 1942 v2 shets-sheet 2 Patented Apr. 4, 1944 UNITED, STATES PATEN T o rrlvclzl MATERIA BLNDVING Philip H. Burdett, Bridgeport, Conn., assignor to Remington Arms Comp any, Inc., liridgepol't,

v'I'his invention relates in general toan agitator, and, in particular, to an apparatus for forming a mixture or combination of granular materials such asused in tracer or incendiary projectiles of the small arms variety.

. The present-device will be particularly described in connection with mixing granular materials of .the kind identified above, but it .will be understoodthat the .apparatus shown and desoribed herein maybe used for mixing other materials and is but one embodiment of the inventon and that modifications thereof'may be made within thescope .of ;the appended claims. i

Heretofore ;the .granular materials used in tracertor incendiary bullets have been mixed by hand and in relatively small quantities. Both of these limitations .have .been deemed expedient Vin view of thesensitivity of the materials which has necessitated taking extreme precautions in order .to prevent accidents.

UIt V`;is an object of the present invention to provide mechanical means for mixing together extremely 4Sensitive materials without liability of explosion or fire. A ffurther Aobject is to provide an apparatus for automatically mlxing relatively large quantities of explosive-or vincendiary materials in a relatively short time. A still .furtherobjectisto provide a blendingtowerhavlng a plurality of mixingmeans for V``conducting' materials downwardly vthrough the tower in sinuously converging and diverging streams.

I'Otherobjects, features and advantages Vof the invention will Vbe more particularly described herei-nafter.

In'thedrawings:

`i'ig'. l-is aside elevation partly in section of'the mixing apparatus of this inven'tion.

i-Fig. 2 is a front view partly in section of the blendingtower.

`Fig.l 3'isa -topview of the blending tower.

iFig. 4 'is a perspective view of 'the complete blending apparatus shown in Fig. 1.

5 is'a-perspective view of the hopper feed means.

Fig. 6 is a side elevation of the receptacle for receiving the mixed materials from the'blending tower.

` lfhe apparatus for mixing the granular ma-` trials is shown in Figs. land 4 and comprises a blending tower indicated generally at ll) having a hopper I I for delivering materials into the upper end of the tower and alreceptacle |2 for rece'ving the mixed materials clischarged from the'lower end of thetower.

Theblending :tower` lz '-Sllppltdgfm oscillation ;in za `verticz'al ;Plane ;by ;supporiins means which comprise a wall 1.3 .fmmeznfmbers I 4 secured kto one ;side thereef, thatower being pivotally mounted on the frame melnhxjs as hereinafter described.. 'Smtamemensz1fcrpscillatinathe tower areinfliated-t L5..

The .blendzing towerjis ;sh zdtailjnifias- 2 and 3.and comprizses-s iellyftectaneulartrqugh 1.20.' QDen-atfe'tqpzan. 4lvH treugh may ;beformd arena-s... table materials .Seth as WQOsL Dress Orleemmnmellwensli-S providedwitha lengiwdiiel. nb., -fscnree tv .er frmed mgrallwth theltack :rallfflfrfherib 23 is reinforced lc transverse websl-atthree spad mms 'whiheonsiiwfie lds -D .itin from therr .Wi theztmrgh' .lhelwses are snitably. drilled as .lat 2-1 -to accommodate .the shafts 28 .an`d129. The ytwo,slnltfts28 are relativel-y long as Compal-.ed 'tofthe-s'ngle;shortzshaft 29, each shaftbeingfsecured driileilibossl by a suitable taper pin arrange'f` tolpass transversely through the boss .and shtt d -'b 'She peened thereon. i i H The' upper'shaft 2;8 comprises means forpivotallyemounfiing the imuhdn theiwmrtsmam l3 which-embodies th'ezpair of spacedsuhstantially Vertical frame members lyvvhichgmaycomprise any suitable materialsnc'h ,asjw'b'od .andto which pare secured a v.pair of crossl'membersll, the upper member having a drilled hole .substantially midway of its ,lengthprovided'vith a fianged loushing 3| o f `.a .stthljegmaterial .Such asbro'nze which ,constitntes a bearingsnrfacefor the shaft 28. vA nut.'32Listhreadedlysecured'on the end of theshaft 2r 8 .to secure the' IatteLinthe bushing; 'in this'manner the'gtrongh-is .pivotally mounted to oscillate'ina snbstantially .vertioal plane.

The lower .shafli 2.8 comprises .a guidelmeans for the tower and totlnsend isv arranged to lprloject into a longitudinal slot'formed infthe 'lower cross vmember 3D. ,IA pair of'lottedplates 339i brassror other materialfare secured .to the, oss memberonopposite.sideslofztheslot toformi z cuned to .sciute within. the..s1itztfi,a note; threadedonto Vthe outerlendnftheshaft.

'rhje third o er intermediate ,snaftfij-zsoizipries means for connecting the tower. tothefosilla fng means 1'5 which may comprisejanexplosionpitoof motor v35 provided with `a ,rotatingfiecoentric 36 sutablvconnected ,bitav rod' j3'| .to thedntr' mediate shlft .2.9. of the towei' `-Iti 'ieiei'hle that the startinlgswitcn for the :motel- 35 befilocated at a distance from the blending tower as, for example, on the opposite side of the wall |3.

The means for blending or mixing the materials, which are introduced by the hopper ||I into the top of the tower, comprises in part a series of symmetrically converging and symmetrically diverging surfaces 40 and 4| respectively, spaced vertically .alt`ernateythroughout the length of the tower,l ,I f-

The converging surfaces 40 are imperforate substantially rectangular plates of cast bronze or other suitable material, provided with smooth upper surfaces and arranged symmetrically in pairs which converge at an .angle of substantially 90 degrees with respect ,to ,eachothen each surface being at an angle of substantially 45 ,de-

grees with respect to the longitudinal axis of xthe tower. As shown in Fig. 3, the' surfaces are substantially equal in length to the depth of the trough and are fixedly secured to the back and side walls thereof by solder joints or other securing me'ans. `.A'suitableape'rture 42 is formed by fthe 'spaced lower'edges 43 of each pair of conyerging 'surfaces 40-adjacent the apex point thereof. 1 i

`suitable means for deflecting the flow of material over the converging surfaces 40 are shown in Fig. 2 and'comprises riffle bars 44 secured to or cast integrally with the surface 40. In the'present embodiment,1eachV s-urface is'provided with a "p'air'of rifile bars disposed diagonallyon the surface and-` in spaced'parallel relation. It will be understood,` however; that Vthe number and disposition of ,the'ri'flie barson each-surface maybe varied-asdesired.

Referring' to Fig. 4, the riflie'bars of each pair off s'ymmetrically converging 'surfaces 40 Vare shown oriented 'in substantiallythe same direction; which 'direction is reversed in the next succeeding pair of conve'rging surfaces, that is to sam-,the riflie bars '44 "of the first pair of converging surfaces `extendfdiagonally downwardly and forwardlytowards the front of the tower, whereas the riflie bars of the next succeeding pair of conyerging] 'surfaces' extend" diagonally downwardly towards the back of the tower; It willV be eviident, therefore, 'thatthe streams of' material flowing down over'the successive converging surfapeswillj be directedback 'and'forth'in sinuous paths whichlie in the planes of'the converging surfaces; w j i All corners andfoints of the riflle bars 44 and converging surfaces 40 are suitably rounded in order'to, reduce'the friction between the materials being mixed'ianfd' the'mixing elements.v

Each pair of diverging surfaces 4| comprises aniinverted V-shfaped plate of cast bronze or other suitable 'material which is soldered at one end to the back wall 24 of the tower and project forwardly to4 the front of the tower, the apex 45 of 'eachlplate being spaced below the apex point of the converging surfaces 40 Vand in vertical 'alignn'ient the'rewith. The upper faces of the platesl 4|] aref'made smooth and diverge at an an'gle ofsubstant'ially 90 degrees with respect to each y'other.` `As shown in Fig. 4, the longitudinal edges -46-of theplatesare not secured to the adjacent wedl'sV of' the tower but' are spaced therefrom'sej'asfto 'form apertures 41 through which materialsl may flow from thefdiverging Surfaces 4| 'onto tlflel surfaces offtheA converging plates '40 located immediatelyjbelowg.

` suitable means for diffusing materials as they flow *downwardly'fromv the converlging surfaces mesh, which extends across the trough and is fixedly secured by solder joints to the side and nto the diverging surfaces'comprises suitable' back walls thereof, in the manner shown.

A second screen 52, similar to the first screen, is similarly secured in the tower at a point lower down, which as shown, is intermediate the third diifusing rod 50 and the adjacent diverging surface 4|. In this connection, it will be noted that the upper and lower screens 52 are disposed substantially equally distant on each side of the pivot 'means 3| of the tower so that each screen receives substantially the same degree' of agitation.

A third and preferably more finely perforated plate 53 is secured Within the tower and comprises typically a 35 mesh screen located below the lowermost diffusing rod 50 and immediately above the material discharging means of the tower; Due to its relatively great distance from the pivot point 3|, the screen 53 is subjected to greater agitation than the screens 52. The means for discharging the mixed materials from the tower comprises a pair of substantially rectangular symmetrically converging plates 54 soldered to the side and rear walls of the tower and arranged at their lower edges to form a discharge aperture 55 as shown in Fig. 2. z

Although five sets of successively arranged converging, clifiusing and diverging means have been shown, it should be understood that the shape, dispositon and number of mixing elements may be varied depending on such considerations as the homogeneity required of the mixture and the speed at which any given quantity of material is to be mixed.

The front wall or face plate 58 of the tower may be formed of plate glass, lucite, bronze or similar materials, and is supported by its edges on longitudinally extending shoulders 59 formed on the edges 60 of the sides Vof the tower as shown in Figs. 3 and 4.

Means for securing the face plate in position comprises a pair of holding plates 62 which consist of relatively thin metal strips secured to the edges 60 'by a plurality of Wing nuts 63 and arranged to overlie the longitudinal edges of the face plate 58. The bottom edge of the face plate is adapted to be supported on an inwardly projecting ledge of an end plate 65, the latterlbeing secured at its opposite ends by screws, to the lower ends of the tower. The upper end of the face plate is shown supported by a transverse rod 65 which is disposed adjacent the front of the tower, the opposite ends of ;the rod being secured in engagement with the inside surfaces of the sides of the tower by suitable screws.

In its assembled position, the rear surface-of the face plate is adapted to closely engage the unsupported ends of the mixing elements and screens above described so that no material may drop down between the ends of the mixing elements and the face plate.

Referring to Figs. 4 and 5, H's the hopper means for delivering the materials' to be mixed to the upper end of the tower and compris'es a rectilinearly tapering conduit provided with a longitudnalpartition 12 adapted -to 'divide the conduit into two is'olated 'conduits 1-3 yof substantially equal size. The lower end of'the 'conduits constitute dischargeiaper'tures 114 located adjacent lthe upper end-of the'blending tower. i

The hopper is shown supported by the wallportion ll 3 of the tower supporting means y'and to `this end-a hole 'lis cutithrough-the wall *[3 'conformin'g to the shape ``of the 'hopper; the l'atter projects through the hole` 15 land 'i's provided i-at its opposite Vend 'with two isola'ted charging 'apertures 76. By providing a wall betweenthe y'c'ha'rging and discharging apertures, these two points are effectively separated and hence the occurrence of an accdent at the blending tower will not endanger the supply of materials at the charging apertures.

The mixed material being discharged from the bottom of the tower is directed into a suitable receiver |2 which, as shown in Fig. 6, comprises a substantially rectangular box 80 adapted to be fixed to the floor or other suitable supporting means. 'The box has an open side 8| and a restricted neck or throat 82, the latter being substantially rectangular and provided with four downwardly converging walls 83 which form a funnel shaped aperture 84 within the receptacle 80. A suitable flange 85 extends around the upper edge of the throat 82 of the receptacle for the purpose hereinafter described.

Suitable means for connecting the fixed receptacle to the oscillating tower is indicated at 86 and comprises a resilient or flexible tube or bellows adapted to fit tightly at one end over the lower end of the blending tower and at its opposite end over the rectangular flange 85 of the receiver.

The materials to be mixed, which in this instance oomprise two different components such as used in tracer or incendiary bullets, are introduced into the tower from the two isolated hopper discharge apertures 14. The tower is then oscillated by energizing the motor 35, whereupon the materials which descend in two streams onto the converging surfaces M) are defiected towards the front of the tower by the riffle bars 44. The two streams of material thus converge into a single stream which flows downwardly through the aperture 42 and impinges on the diffusing rod 50 which spreads the material over the surface of the screen 52. The material is then slfted through the screen, due to the agitation thereof, onto the diverging surfaces 4| which divides the material into two separate streams, each of which flows through an aperture 41 onto the next pair of converging surfaces. Here the materials again converge downwardly in the manner above described except that the rile bars 44 of the second pair of converging surfaces deflect the streams toward the back of the tower. Thus, it Will be evident that as the materials fall down through the tower they are continuously being united into a single stream, divided into separate streams, diffused over the surface of the screens and sifted through the screens; and throughout these treatments the streams of materials are being defiected back and forth in a sinuous path. As a result, a substantially homogeneous mixture is obtained in a relatively short time; and further, since all mixing elements are fixed with respect to the tower the material under treatment encounters no relatively moving parts, and hence the probabilty of accidents or explosions due to friction is substantially eliminated.

What i's claimed is: i I

l. A tower .forvmixing materials comprising alternately arranged pairs of vertically spaced symmetrically converging and diverging surfaces means onsaid converging surfaces for defiecting'the flow of materials thereover; and'mean's at the apices of said converging'surfaces extending transversely to and in the path of said materials 'to diifuse and distribute the materials vbeing dischargedfrom said converging surfaces onto said diverging surfaces. w p 72."A tower'for 'mixing materials ;comprising alternately arranged pairs ofvertically spaced symmetrically converging and 4divergingl planar surfaces; and pairs of spaced parallel riflie bars on said converging surfaces for deflecting the fiow of materials rectilinearly thereover, said bars being arranged diagonally thereon, each set of bars on suocessive converging surfaces being disposed in a direction reverse to that of the preceding set.

3. A tower for mixing materials comprising alternately arranged pairs of vertically spaced symmetrically converging and diverging imperforate surfaces; a fixed rod arranged at the apices of said converging surfaces extending transversely to and in the path of said materials to diffuse and distribute the material being discharged from said converging surfaces onto said diverging surfaces; and perforated surfaces interposed between said diifusing means and said diverging surfaces.

4. A tower for mixing materials comprising alternately arranged pairs of vertically spaced symmetrica'lly converging and diverging imperforate surfaces; means at the apices of said converging surfaces to diffuse and distribute the material being discharged thereon from said converging surfaces onto said diverging surfaces; perforated surfaces interposed between said diffusing means and said diverging surfaces; and riffie means on said converging surfaces for deflecting the flow of material thereover.

5. In an apparatus for mixing materials, the combination with a Vertical tower and means for oscillating said tower; -of means for delivering materials to said tower; means for mixing said materials by the oscillation of said tower comprising alternately arranged pairs of vertically spaced symmetrically converging and diverging surfaces; and riflle means on said converging surfaces for defiecting the flow of materials thereover.

6. In an apparatus for mixing materials, the combination with a Vertical tower and means for oscillating said tower; of means for delivering materials to said tower; means for mixing said materials due to the oscillation of said tower comprising alternately arranged pairs of vertically spaced symmetrically converging and diverging surfaces; riffle means on said converging surfaces for defiecting the fiow 'of materials thereover; means at the apices of said converging surfaces to diffuse and distribute the materials being discharged thereon from said oonverging surfaces onto said diverging surfaces; and means for discharging the mixed materials from said tower.

'7. In an apparatus for mixing materials, the combination with a tower and means for oscillating said tower; of means for supporting said tower to oscillate in a Vertical plane, said supporting means having a slot; and means mounted in said slot for delivering materials into said tower, said delivery means comprising isolated vof, said discharging apertures being disposed adjacent the upper end of said tower.

. 9. In an apparatus for mixing materials, the

' combination with a tower and means for oscillating said tower; of means for supporting said tower to oscillate in a Vertical plane, said supporting means having a slot; and hopper means mounted in said slot for delivering the materials into said tower, said hopper means comprising a pair of rectilinear tapering isolated conduits having discharge aperturesadjacent the top of said tower and on one side of said supporting means, and charging apertures on the opposite side of said supporting means.

PHILIP H. BURDETT. 

